getnpsi
+1y
Those are a solid choice. Plentiful too. You can google "miata tire calculator" i would say 69% of people who have a tire size question use that site and never owned a miata . most 17 inch tires for passenger cars in 45-60 series are going to be not far off from stock truck balloon size. 215/50/17 is super close. If those chevy wheels need a 225 to be safer then its still not off much.
I didn't index my bars, just turned the drivers side 7 turn and the passenger side 8.5 turns. In rear I took out one rear leaf and put in 2 inch blocks. You can tell the truck is lowered but it performs almost all of its stock configuration. I do plan on reindexing and putting in rear air shocks but no hurry, I drive 800 miles a week as-is.